2. Questions Bank
  3. 12th Class
  4. Physics
  5. Magnetism

12th Class Physics Magnetism Question Bank MCQ - Moving Charges and Magnetism

  • question_answer
    A solenoid of Length 0.6m has a radius of 2 cm and is made up of 600 turns. If it carries a current of 4 A, then the magnitude of the magnetic field inside the solenoid is:

    A) \[6.024\times {{10}^{-3}}T\]    

    B) \[8.024\times {{10}^{-3}}T\]

    C) \[5.024\times {{10}^{-3}}T\]    

    D) \[7.024\times {{10}^{-3}}T\]

    Correct Answer: C

    Solution :

    (c) \[5.024\times {{10}^{-3}}T\] Here,    \[n=\frac{600}{0.6}=1000\,\,turns/m,\,l=4\,A\]             \[l=0.6\,m,\,r=0.02\,m\because \frac{l}{r}=30\,i.e.,\,l>>r\] Hence, we can use long solenoid formula, then            \[\therefore \,\,\,\,\,B={{\mu }_{0}}nl=4\pi \times {{10}^{-7}}\times {{10}^{3}}\times 4=50.24\times {{10}^{-4}}\]             \[=5.024\times {{10}^{-3}}T\].


You need to login to perform this action.
You will be redirected in 3 sec spinner